arXiv subjects

Sebastián Urrutia Quiroga

Publications and source records attributed to Sebastián Urrutia Quiroga.

6 recordsLinked to original sources

arXiv2026

Flavorful Lepton Number Violation at the EIC

We explore the prospects of detecting flavorful lepton number violation at the Electron-Ion Collider (EIC) through resonant production of heavy neutral leptons (HNLs), resulting in $e^- p \to \ell^+_α+ k\, j+X$, where $α\in \{e, μ, τ\}$ and $k$ denotes the number of jets. We work in the $ν$SMEFT framework of the Standard Model Effective Field Theory augmented with $n$ singlet HNLs, one of which is in the mass range $10-100$~GeV, within kinematic reach of the EIC. To explore the EIC sensitivity, we focus on the HNL production mechanism induced by mixing with light neutrinos. We study kinematic distributions for signal and backgrounds, including hadronization and detector effects, and suggest a set of cuts to minimize backgrounds. In the mass range considered, we find that the EIC with muon detection capabilities and an integrated luminosity of $100~\mathrm{fb}^{-1}$ can reach sensitivities comparable to the strongest direct (LHC) and indirect constraints, and is especially relevant in the $ν$SMEFT framework beyond dimension four. Our study motivates further assessment of muon detection capabilities at the EIC and $τ$ hadronic reconstruction, as well as a more general theoretical analysis involving production mechanisms mediated by higher-dimensional operators in the effective theory.

hep-ph↗

arXiv2025

Dissecting Lepton Number Violating Interactions in the Left-Right Symmetric Model: $0νββ$ decay, Møller scattering, and collider searches

In the context of the left-right symmetric model, we study the interplay of neutrinoless double beta ($0νββ$) decay, parity-violating Møller scattering, and high-energy colliders, resulting from the Yukawa interaction of the right-handed doubly-charged scalar to electrons, which could evade the severe constraints from charged lepton flavor violation. The $0νββ$ decay amplitude receives additional contributions from right-handed sterile neutrinos. The half-life, calculated in the effective field theory (EFT) framework, allows for an improved description of the contributions involving non-zero mixing between left- and right-handed $W$ bosons and those arising from exchanging a light right-handed neutrino. We find that the relative sensitivities between the low-energy (or high-precision) and high-energy experiments are affected by the left-right mixing. On the other hand, our results show how the interplay of collider and low-energy searches provides a manner to explore regions that are inaccessible to $0νββ$ decay experiments.

hep-ph↗

arXiv2025

Neutrino-less double beta decay in the $ν$ Standard Model

We perform a comprehensive study of the $3+3$ Type-I seesaw model for a broad range of right-handed mass scales (from keV to 10 TeV). We take into account and, in some cases, update the constraints from a large number of high- and low-energy experiments and study the implications on neutrino-less double beta ($0νββ$) decay experiments. We illustrate our findings through profile likelihood plots for the half-life $T_{1/2}^{0ν}$ and two-dimensional plots correlating $T_{1/2}^{0ν}$ to neutrino masses. We find that in this simple class of models for Majorana neutrino masses, current and next-generation $0νββ$ decay experiments have a broad discovery potential in both the normal and inverted orderings of the spectrum of light active neutrinos.

hep-ph↗

arXiv2025

Neutrinoless double beta decay with light sterile neutrinos: the contact terms

We study neutrinoless double-beta decay in extensions of the Standard Model that include $n$ right-handed neutrino singlets, with masses $m_s$ below the GeV scale. Generalizing recently developed matching methods, we determine the $m_s$ dependence of the short-range $nn \to pp$ couplings that appear to leading order in the chiral effective field theory description of neutrinoless double beta decay. We focus on two scenarios, corresponding to the minimal $ν$SM and left-right symmetric models. We illustrate the impact of our new results in the case of the $ν$SM, showing a significant impact on the neutrinoless double-beta decay half-life when $m_s$ is in the 200-800 MeV range.

hep-ph↗

arXiv2024

Testable leptogenesis and $0νββ$ decay in extended seesaw model

We investigate the possibility of observable neutrinoless double beta decay $( 0 νββ)$ and viable leptogenesis within a low-scale extended inverse seesaw mechanism with additional sterile neutrinos. General effective field theory (EFT) considerations suggest that if there are experimentally observable signatures in $0 νββ$-decay and a lepton asymmetry generated by heavy right-handed neutrino decays, thermal leptogenesis is likely to be unviable. However, in this work, we show that in the context of low-scale leptogenesis, one can obtain the observed baryon asymmetry of the universe and observable signatures of $0 νββ$ decay in the presence of additional sterile neutrinos. In this framework, the light neutrino masses are suppressed by the extended seesaw parameter, $μ$, thereby allowing for $\mathcal{O}(10\, \mathrm{TeV})$ right-handed (RH) neutrinos, while avoiding small Yukawa couplings as in other neutrino mass models and near degeneracies in the RH neutrino spectrum as required by the low-scale leptogenesis paradigm. Contributions to the $0 νββ$-decay rate from additional sterile neutrinos can be appreciable, while the corresponding contributions to the early universe lepton asymmetry washout rate are suppressed by other parameters not entering the $0 νββ$-decay amplitudes. We show that for keV-MeV scale, sterile neutrinos future ton-scale $0νββ$-decay experiments offer potential signals while maintaining viable leptogenesis.

hep-ph↗

arXiv2024

TeV-scale Lepton Number Violation: Connecting Leptogenesis, Neutrinoless Double Beta Decay, and Colliders

In the context of TeV-scale lepton number violating (LNV) interactions, we illustrate the interplay between leptogenesis, neutrinoless double beta ($0νββ$) decay, and LNV searches at proton-proton colliders. Using a concrete model for illustration, we identify the parameter space where standard thermal leptogenesis is rendered unviable due to washout processes and show how $0νββ$ decay and $pp$ collisions provide complementary probes. We find that the new particle spectrum can have a decisive impact on the relative sensitivity of these two probes.

hep-ph↗